


Happy 18th

by Myqueenmarceline



Category: Adventure Time
Genre: Aged-Up Character(s), F/M, Finnceline, Hetero Sex, Plot What Plot/Porn Without Plot, Sex, Sexual Content, god I need to update my archive, just that
Language: English
Status: Completed
Published: 2017-01-16
Updated: 2017-01-16
Packaged: 2018-09-17 23:31:19
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,509
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9351281
Author URL: https://archiveofourown.org/users/Myqueenmarceline/pseuds/Myqueenmarceline
Summary: Some Finnceline PWP I wrote ages ago because I'm finally updating my profile.





	

On the day of his eighteenth birthday, Finn had been having a really good day. Jake had thrown him a surprise party with everyone who would come. Even Party God was there, and he didn’t come to just any party.

  
Marceline had also wanted to see him, but didn’t want to come to the party and told Jake her present was for Finn’s eyes only. He didn’t care and trusted her, so after some arguing about how he was old enough, Jake finally agreed for him to go. Finn was glad Jake wasn’t there when he saw what Marceline was wearing. A cutoff top exposing her stomach with just the band logo on it combined with a short black skirt and thigh high socks that just wouldn’t stay up. She told him she was taking him out drinking.

  
After wandering around for about half an hour in the forest near her cave home, Marceline came to a small decrepit opening of a cave. A skeleton was guarding the door, but he quickly moved aside for Marceline.

  
The entire place looked shady, with dark lights and a lot of creatures that looked pretty evil to Finn just sitting at tiny booths and tables. Marceline sauntered up to the bar, nodding at a few people who looked at her.

  
The bartender pulled out a bottle that wasn’t even labeled. It just had three Xs on it, and it looked almost black.  
She held one out to him, and after a few seconds of hesitation (he’d been drinking before but that was just a bit of champagne), he tried it and winced. It burned in his mouth, throat, all the way down to his stomach, and made his head spin a little. He refused another one, and she only took two.

  
Marceline then asked him to go to the bathroom with her, saying she didn’t want to go alone. He shrugged and did it. It wasn’t like he wanted to drink more and he didn’t have anyone else to talk to.

  
He stiffened up when she turned around and kissed him, forked tongue lengthening and trying to push it into his mouth.  
“What are you doing?” Finn asked, pushing her away. Despite her being stronger than him, she let him do it.

  
“Listen, I’m horny. I don’t want to take home anyone here, and you’re pretty cute. I don’t want a relationship, but maybe we can be friends with benefits?” Marceline asked, looking at him hopefully.

  
“Well, I guess so. How do you want to do this?” Finn asked, feeling a little awkward but ready to try it out.

  
Marceline was the only girl who hadn’t abandoned or rejected him in their five years of knowing each other, and she was one of his best friends. They were both adventurous and loved to travel the land of Ooo. Even if they didn’t hang out very often, whenever they did it was fun and relaxing. She was his chill friend.

  
Besides, it wasn’t as if he hadn’t checked her out a few times. Even if he’d been flustered that one time he’d accidentally seen her naked, that was years ago when he didn’t quite understand what he saw.

  
She had a fairly nice body, and even if she was a little pale, he couldn’t deny he was a bit attracted to her.

  
He chuckled a bit as Marceline pulled his hat off, ruffling his hair affectionately. She kissed down his neck, pulling away as he squirmed. He was a little nervous, since although she was a vegetarian there was still the possibility she wouldn’t be able to control herself. He didn’t know, she was the only vampire left.

  
She kissed him again instead, and he kissed back this time. She smiled against his lips as his hands wandered to her chest. He pushed her shirt up shivering a little at the feeling of her cold body, but it wasn’t exactly unpleasant.

  
Her breasts weren’t big, but they weren’t small either. She seemed to like it when he touched them, grinding up against him a little when he did so. Her hands rubbed at his shoulders, feeling the muscles there. He was strong, but not overly muscular. His muscles weren’t readily visible through his shirt, but they were definitely there..

  
Finn still didn’t quite have a defined stomach mostly due to baby fat that simply refused to leave. Marceline poked at it a little before moving her touch a little lower, tracing his hips before skating over the waistband of his shorts. Both of her hands grabbed his crotch at the same time, pushing her breasts together a little. Finn squeezed them a bit harder as her hands rubbed circles in his erection.

  
He moaned, deciding to get to the main event.

She smiled at him, pulling her skirt up and her panties down. He reached out hesitantly, putting his hands on her thighs first. Her skin was slightly damp as he moved to her inner thighs, but he didn’t know what it was from.

  
After a moment, he took the initiative, pressing a finger inside her. She giggled at him, taking him by the wrist and pulling him backwards with her so she was sitting on the counter, just in front of the sink.

  
“Come on, I can take more than that. I won’t break.” Marceline teased, spreading her legs as wide as she could with her underwear still tangled around her lower thighs. He flushed, putting in another two.

  
She was a bit cold inside to the touch, but it was fairly slick and easy to move around. He pressed his thumb against her clit, greatly enjoying the faint flush that appeared on her cheeks and the shaking breaths it earned him.

  
He spread her open then retracted his fingers. From there, he was confused for a moment. The only reason he knew about sex was an old magazine he’d found, and in that one the girl was lying down and the guy was behind her.

  
He shrugged, grabbing Marceline’s hips and turning her around so she was facing the mirror. She yelped, but then rolled her eyes and stuck her butt out. Finn blushed, spreading her but hesitating about actually entering.

  
“Can I do it?” Finn asked, wanting one last bit of confirmation. She snarled back a yes, and so he did it.

  
He shuddered a little, realizing that this was much better than his hand. Marceline impulsively pushed him away, a bit before pushing back onto him. Finn got the idea, quickly starting to let out short thrusts.

  
The sound was rather odd, sort of like clapping. Finn chuckled a little at the thought, and Marceline looked at him in the mirror, confused. He just shook his head and kept at it, reaching around to play with Marceline’s clit again.

  
They were both having a very good time, with Marceline’s face changing to a lovely shade of dark pink.  
She was letting out quiet groans, and pressing back into him. He leaned forwards over her back, and pressing kisses onto her back. Marceline made eye contact with him in the mirror and let out a louder moan.

  
Then, the door handle jiggled. Finn froze, wincing as he heard someone asking who was in there, and if they could hurry up.  
“Just a few minutes! Trust me, you don’t want to come in here!” Marceline said, winking at Finn and making him blush.  
Finn continued on, moving faster and just deciding to try his best to fuck her into the counter and make her feel good.  
He shuddered, knowing that he was getting close as Marceline would tense up, trying to keep him inside her.

  
She put a hand over her mouth, but Finn wanted her to let out more of those quiet sounds. It let him know he was doing well.  
In the end, he had the hand on her clit holding her hips there and his other hand was back up under her shirt.

  
He came first, and he just continued to thrust. It felt so odd, since the blood was draining from his lower half but he was still trying for it. He knelt down and bit at her inner thighs, and she finally came.

  
She was even more relaxed than she was before, helping him clean the both of them up and get dressed again. She then walked out like nothing had happened, even though the both of them were clearly very disheveled. She ordered something a little milder, she called it wine. Finn thought it was much better than the other one, and had a glass and a half, with Marceline finishing the bottle for him.

  
The rest of the night involved a little bit more drinking, and then heading back to Marceline’s place for a new action movie Marceline had found. They didn’t do anything else, and he somehow managed to fall asleep on her rock hard couch. The next day they didn’t mention it, but they would probably do it again eventually sometime.

  
End


End file.
